Abstract

Ultrafast spin current is an essential ingredient for high-speed spintronic devices. It is anticipated that antiferromagnets can play to their strength of ultrafast spin dynamics on the picosecond timescale to produce and manipulate picosecond spin currents. In this talk, I will introduce our understanding on the optical generation of picosecond spin current in metal/antiferromagnetic heterostructures at zero magnetic field and room temperature. The spin current originates from a magnetic-dipole nonlinear optical process due to the broken mirror symmetry. We propose a model based on the symmetry to quantitatively explain the experimental observations. Owing to the ultrashort time scale, the manipulation of the ultrafast spin current is different. We find that the direction of the spin polarization of the ultrafast spin current can be strongly modulated after the reflection from an antiferromagnet.

Biography

Di Wu, Di Wu received his B.S. degree in Physics and Ph.D. degree in Condensed Matter Physics from the Department of Physics, Fudan University in 1997 and 2001, respectively. During his graduate studies, he visited the Hong Kong University of Science and Technology and the Max-Plank Institute for Microstructure Physics in Germany for a short period of time. After his Ph.D., he worked as a postdoctoral fellow at Department of Physics, University of Utah and the University of California, Riverside, U.S.A. In 2007, he joined Nanjing University and obtained a professorship. His research focuses on spintronics, particularly spin transport in magnetic insulators. He received the Excellent Youth Science Fund and Outstanding Youth Science Fund from the National Science Foundation of China.